V8

基础

V8 中的一些概念

GlobalValue JS 的变量

LocalValue V8 的变量

rusty_v8

使用 v8 运行 JS 代码，并为 JS 环境注入 rust 函数

rusty_v8 已经更名为 v8

依赖 v8 = "0.74" serde_v8 = "0.37"

fn print(
    scope: &mut v8::HandleScope,
    args: v8::FunctionCallbackArguments,
    mut _rv: v8::ReturnValue,
) {
    let result = args.get(0).to_string(scope).unwrap();
    println!("Rust says: {}", result.to_rust_string_lossy(scope));
}

fn main() {
    // initializa v8 engine
    init();

    // create a new isolate
    let params = v8::CreateParams::default();
    let isolate = &mut v8::Isolate::new(params);

    // create handle scope
    let handle_scope = &mut v8::HandleScope::new(isolate);
    // create context
    let context = v8::Context::new(handle_scope);
    // create context scope
    let context_scope = &mut v8::ContextScope::new(handle_scope, context);

    // 为 JS 提供 rust 函数
    let bindings = v8::Object::new(context_scope);
    let name = v8::String::new(context_scope, "print").unwrap();
    let func = v8::Function::new(context_scope, print).unwrap();
    bindings
        .set(context_scope, name.into(), func.into())
        .unwrap();

    // js code
    let glue_code = r#"
      'use strict';
      ({print}) => {
        globalThis.print = print;
      };
    "#;
    // 运行 glue 代码，把 rust 函数绑定到 JS
    let glue_code = v8::String::new(context_scope, glue_code).unwrap();
    let script = v8::Script::compile(context_scope, glue_code, None).unwrap();
    if let Some(result) = script.run(context_scope) {
        let func = v8::Local::<v8::Function>::try_from(result).unwrap();
        let v = v8::undefined(context_scope).into();
        let args = [bindings.into()];
        func.call(context_scope, v, &args).unwrap();
    }

    // js code
    let source = r#"
      print('Hello World!');
    "#;
    let source = v8::String::new(context_scope, source).unwrap();
    let script = v8::Script::compile(context_scope, source, None).unwrap();
    script.run(context_scope).unwrap();
}

fn init() {
    let platform = v8::new_default_platform(0, false).make_shared();
    v8::V8::initialize_platform(platform);
    v8::V8::initialize();
}

rust